The Structural Role of Transition Metal Oxides in Borate and Phosphate Glasses Studied by Dipolar Magnetic Resonance Techniques of Quadrupolar Nuclei

• Grant number: 23/17069-5
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: April 01, 2024
• Status: Discontinued
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal Investigator: Hellmut Eckert
• Grantee: Rafaella Bartz Pena
• Host Institution: Instituto de Física de São Carlos (IFSC). Universidade de São Paulo (USP). São Carlos , SP, Brazil
• Associated research grant: 13/07793-6 - CEPIV - Center for Teaching, Research and Innovation in Glass, AP.CEPID
• Associated scholarship(s): 25/06921-8 - Development of Wideband Excitation Strategies for Quadrupolar Nuclei: Application to Structural Studies of Glasses, BE.EP.PD

Abstract

During the past decades, the incorporation of transition metal oxides into glasses has been the focus of significant attention, owing to their unique linear and non-linear optical properties such additives bestow upon oxide glasses, highlighting their potential of replacing lead as an ingredient in this respect. Little is known about the structural role of the transition metal oxide component, which, being an intermediate oxide, can serve as a network modifier or as a network former component. Aside from this fundamental research question, the elucidation of glass structure is also very important from the viewpoint of applied technology, focused on the development of composition-structure-function relationships. Nuclear magnetic resonance (NMR) offers an element-selective, inherently quantitative and experimentally very flexible approach for the structural elucidation of glasses. NMR can give clear-cut and quantitative answers about the extent of network polymerization, the spatial distribution of the network former and network modifier species, and the structural roles of network formers, network modifiers, and intermediate oxides introduced into these networks. These results facilitate our understanding of the influence of glass compositions upon the physical properties of these glasses. The present postdoctoral project has a dual mission, both, in terms of the fundamental understanding of the glassy state and in terms of developing advanced solid-state NMR methodology of quadrupolar nuclei as a structural tool in glasses. In terms of the fundamental description of the glassy state, the present project seeks new insights about the structural role of transition metal oxides in terms of their potential function as network formers or as network modifiers. From the perspective of NMR methodology, a specific mission of this project is to emphasize and develop the potential of non-routine, more advanced NMR experiments involving quadrupolar nuclei in glasses, and to exploit them as structural probes for developing structure-property correlations in glasses.